JP5224871B2 - Equipment monitoring system using wireless communication - Google Patents

Description

The present invention, cracking of civil engineering facilities and the surrounding ground, subsidence, about the facility monitoring system that can grasp the strange shape of the progression of slippage.

Conventionally, civil engineering facilities represented by concrete structures and surrounding grounds are deformed such as cracks, settlements, and slips due to various causes. It is necessary to manage the progress of the deformation by monitoring such as measurement. In order to effectively and efficiently maintain a civil engineering structure such as a power plant, it is necessary to estimate the cause of the deformation that has occurred in the structure and take measures such as repairs as necessary. If there is no urgent need for repairs, the progress of cracks in the structure, the subsidence of the slopes around the structure, and the progress of the deformation, such as changes in the slope, will be grasped, and A monitoring system is needed to estimate the cause.
The conventional equipment monitoring system is to construct a monitoring system by installing a sensor at a deformed location and connecting it to a data recording location with a cable. (For example, Patent Document 1)
No. 2005-033475 public information Also, the construction of a system to monitor equipment by wireless measurement without connecting the sensor with a cable is being studied, and a measurement device capable of miniaturization and power saving using the wireless measurement system Discloses a monitoring system that can easily collect physical quantities (Patent Document 2). In this invention, only when the wireless transmitter (slave unit) receives a wireless signal indicating a wireless transmission request from the outside (master unit), the physical quantity measured by the sensor is transmitted by the transmission circuit built in the wireless transmitter. A wireless signal is transmitted, and a plurality of wireless transmitters connected to sensors are arranged in a building, and the wireless transmitter and data collection are performed using a wireless technology such as wireless LAN or Bluetooth (registered trademark). The wireless transmission request and the physical quantity measurement result are transmitted directly to the computer. JP 2001-338382 A

However, the conventional equipment monitoring system described in Patent Document 1 has a measurement system constructed by connecting a sensor and a data recording device with a cable, and thus has the following problems.
(1) Enormous costs are required when targeting a vast range or area.
(2) Cables need to be laid along with the measurement, but there are places where cables cannot be traversed on public roads.
(3) There are some places where it is difficult to enter for safety when you want to check the condition of the facility temporarily after an earthquake.
Further, the invention described in Patent Document 2 has the following problems when used as a monitoring system for civil engineering facilities.
(1) Since it is intended for measurement in a building, it is assumed that the wireless transmitter and the data collection computer can directly transmit and receive, and there is a limit to the arrangement range of the wireless transmitter. The main object of the present invention is monitoring of outdoor facilities and surrounding ground, and it is necessary to manage a wide area in a plane.
(2) Although some consideration has been given to power saving and longer life of the power supply, it has not been able to secure a power supply life that can withstand monitoring systems such as outdoor equipment. Especially in the monitoring of facilities located in narrow spaces, it was necessary to achieve a long-term (several years) power supply life due to the artificial reduction related to power supply replacement. Furthermore, the reliability as a long-term equipment measurement system was insufficient.
(3) A method of measuring at the slave unit only when a wireless transmission request from the master unit is received is used, but this is not suitable for regular monitoring of equipment. There was a need for a technology that can reliably perform regular measurements at regular sampling intervals while achieving a practical power supply life. At the same time, it was necessary to be able to handle extraordinary measurements in an emergency.
(4) Since a measurement device incorporating a dedicated strain sensor and a wireless transmitter is used and measurement other than strain cannot be performed, the number and types of physical quantities that can be measured are limited. For use as maintenance management of outdoor equipment, etc., not only strain gauges, but also physical sensors related to equipment such as extensometers, crack displacement gauges, inclinometers, and physical quantities related to environmental conditions such as thermometers It was necessary to ensure connectivity. In addition, due to the necessity of temperature correction of physical quantities, it has been necessary to measure a plurality of physical quantities simultaneously with a single measurement system.

The present invention was made to solve the above problems, and in a facility monitoring system capable of grasping deformations such as cracks, subsidence, landslides in civil engineering facilities and surrounding ground, surface multipoint measurement is possible, The object is to provide a facility monitoring system that does not require long-term power supply replacement.
Another object of the present invention is to provide a highly reliable equipment monitoring system that can cope with temporary measurement in an emergency.
It is another object of the present invention to provide a measuring device for an equipment monitoring system that has good connectivity with commercially available sensors.

The present invention has been made to achieve the above object, and the invention according to claim 1 collects and records a plurality of measuring devices for measuring a predetermined physical quantity and information obtained by the measuring devices. In a facility monitoring system using wireless communication comprising a data recording device and a personal computer that controls the data recording device, a predetermined one of the measurement devices is the data recording device or the plurality of measurements by relay wireless communication. Perform wireless communication with the rest of the device, synchronize the measurement time with the rest of the measuring device by intermittent transmission and reception and adjust the communication path, measure the physical quantity at a predetermined sampling interval, and obtain the obtained physical quantity measurement value An equipment monitoring system using wireless communication, wherein the equipment is transmitted to the data recording device.
When the plurality of measurement devices perform relay wireless communication, the measurement devices can be arranged beyond the range where the data recording device can directly communicate, and a wide range can be measured in a plane. In addition, by using intermittent transmission / reception to enter a standby mode except when necessary, a practical power supply life due to power saving can be achieved.

According to a second aspect of the present invention, the wireless communication according to the first aspect is characterized in that a result of measuring a predetermined physical quantity by the plurality of measuring devices is stored and then transmitted to the data recording device. Is an equipment monitoring system using
Thus, by storing and accumulating data with the measurement device, the risk of data loss can be reduced, and a highly reliable measurement system can be constructed. In addition, the number of times of data transmission to the data recording device can be reduced, and power consumption can be reduced accordingly.

The invention according to claim 3 is the timing when the measurement device continuously enters the trigger signal reception mode at a constant interval and receives the trigger signal from the data recording device or the trigger signal transferred from another measurement device. The facility monitoring system using wireless communication according to claim 2, wherein the physical quantity is measured and the result is transmitted to the data recording device.
As a result, the temporary measurement and the temporary data transmission can be performed by the trigger signal from the data recording device, so that the measurement can be performed at an arbitrary timing when necessary in addition to the regular measurement. In addition, the measurement apparatus can suppress the power consumption to the minimum by intermittently entering the trigger signal reception mode within the minimum necessary range.

According to a fourth aspect of the present invention, the wireless communication according to the third aspect is characterized in that a communication path of the measuring device and an alternative communication path when there is a measuring device that cannot communicate are determined in advance. The equipment monitoring system used.
This makes it easy to check the communication path by intermittent transmission and reception, and minimizes the number of communications, by predetermining the communication path during normal operation of the measuring device and the alternative communication path (detour path) at the time of trouble. Therefore, power consumption can be suppressed.

The following effects can be obtained by constructing an equipment monitoring system using a wireless measurement system of the present invention.
(1) It is possible to measure even at difficult locations (such as high places and narrow areas).
(2) Measurement system construction costs can be greatly reduced (generally about 1/5).
(3) Since it is possible to measure multiple points at the same cost, it is possible to perform highly accurate equipment diagnosis.
(4) Since the work related to cable installation such as securing the cable installation location can be omitted, a measurement system can be constructed quickly.
(5) Once a measurement system is constructed, measurement points can be easily added.
(6) Even after the occurrence of a change in the measurement location due to a natural disaster or the like, measurement is easy to continue because there is no influence of cable breakage or the like.
(7) By storing data even in the slave unit, highly reliable measurement can be performed.
In addition, by extending power supply life to a practical level by reducing power consumption and improving power supply capacity, the frequency of battery replacement can be reduced, and maintenance costs associated with replacement can also be reduced.
Furthermore, the improved sensor connectivity makes it possible to use a variety of general-purpose sensors and increases the types of data that can be handled. In addition, by connecting to a plurality of sensors, measurements such as a thermometer and a displacement meter can be performed simultaneously at one point, and data accuracy is improved.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. The technical scope of the present invention is not limited to this embodiment.

[Equipment monitoring system using wireless communication]
FIG. 1 shows a configuration diagram of an equipment monitoring system using wireless communication according to the present invention. In FIG. 1, 1 is a data recording device, 2 is a measurement system according to the present invention, 3 is a measurement device for measuring a predetermined physical quantity, 4 is a sensor suitable for measuring a predetermined physical quantity, and A is a wireless communication according to the present invention. Is an equipment monitoring system using
As shown in the figure, the radio equipment monitoring system A in this embodiment is composed of a data recording device 1 and a measurement system 2, and the measurement system 2 further includes a plurality of measurement devices 3 and each of the measurement devices 3. The sensor 4 is connected to correspond to the above (a crack displacement meter is shown in the figure).
The physical quantity is measured by taking an electrical signal from each sensor 4 into a measuring device 3 connected to each sensor 4 and processing the data.

The data transmission method from each measuring device 3 differs depending on whether or not each measuring device 3 is within the communication range of the data recording device 1. That is, when each of the measuring devices 3 is within the communication range of the data recording device 1, data is transmitted by direct wireless communication between them.
When each of the measuring devices 3 is out of the communication range of the data recording device 1, the data is transferred to the data recording device 1 by relay wireless communication via another adjacent measuring device 3.
As the radio frequency band, a specific low power radio in the 2.45 GH band is used. The communication distance between the measuring devices 3 can be up to 200 m. Next, the configuration of the measuring device 3 is shown in FIG. In FIG. 2, (a) shows the configuration diagram of the measuring device 3 when there is one connecting portion to which the sensor is connected, and FIG. 2 (b) shows the configuration diagram of the measuring device 3 when there are a plurality of connecting portions (in this case, two). is there.

  As shown in FIG. 2A, the measuring device 3 includes a timer unit 11 that transmits signals at regular intervals, a power source unit 12 that outputs power, a control unit 13 that controls measurement of physical quantities and wireless transmission and reception, and physical quantities. Storage unit 14 for storing the measurement results of the above, wireless transmission / reception unit 15 for transmitting and receiving signals and data wirelessly with the outside, conversion unit 16 for amplifying the detection signal from the sensor and converting it into a digital signal, and a predetermined physical quantity It is comprised from the connection part 17 connected with the sensor which detects this.

  The timekeeping unit 11 has a function of transmitting a signal at regular intervals and notifying the control unit of the timing of periodic measurement or the like. A so-called various real-time clock (hereinafter referred to as RTC) used in a computer system can be appropriately selected and used. RTC accuracy and power consumption are inversely related, but for civil engineering applications, it is generally better to reduce power consumption at the expense of RTC accuracy to reduce power consumption of the entire measuring device. ing.

  The power supply unit 12 supplies power for operating the measuring device 3 and the sensor 4 (see FIG. 1). The power supply life to be secured is determined from the required specifications for civil engineering measurement, but is generally set to 1 to 3 years. What is necessary is just to set a power supply voltage from the relationship with the component of the measuring device 3, and generally is set to 3.0V-6.0V. The power source can be appropriately selected from commercially available batteries, but for civil engineering measurements, lithium batteries (thionyl lithium chloride batteries, lithium manganese dioxide batteries, etc.) are used from the viewpoint of power supply life and voltage stability. Most suitable.

  The connection portion 17 is a connection port with the sensor 4. Via the connection unit 17, an activation or measurement command is transmitted to the sensor 4, power is supplied, and a measurement result from the sensor 4 is transmitted to the conversion unit 16. In the connection unit 17, a sensor system that can be connected may be set in consideration of connectivity with a commercially available sensor. Since 80% of the civil engineering measurement sensors are strain conversion type sensors, it is suitable to set so as to be compatible with the strain conversion type sensors. Further, as shown in FIG. 2B, a plurality (two in the drawing) of the connecting portions 17 may be provided. By doing so, for example, the temperature and the physical quantity at the same point can be measured simultaneously, the temperature correction of the physical quantity becomes easy, and the measurement accuracy can be improved.

The converter 16 performs processing (generally called A / D conversion) for converting a continuous signal (analog signal) from the sensor 4 into a digital signal that can be processed by the controller 13. The A / D conversion process performed by the conversion unit 16 is a general process, and commercially available parts can be appropriately selected and used. The resolution of A / D conversion can be used from 8 bits, but is preferably 16 bits or more in order to ensure practical data accuracy such as measurement of a minute crack width.
The wireless transmission / reception unit 15 has a function of transmitting data and signals from the measuring device 3 and receiving data and signals from the outside wirelessly. The wireless transmission / reception unit 15 includes an antenna unit (not shown), and wireless transmission / reception is performed via the antenna unit.

  The measuring device 3 is installed in a waterproof container except for the antenna portion. The antenna part has a completely waterproof structure and is installed outside the container. The waterproof container needs to ensure that water does not enter even when it rains. In general, a specification of JIS IPX5 (jet-proof type) or higher is selected as the JIS protection class. Furthermore, it is preferable that it is more than JIS IPX6 (waterproof type).

[Measurement method]
Next, the measurement system according to the present invention will be described with reference to the measurement flowchart shown in FIG.
FIG. 3A is an overall flowchart of the measurement system according to the present invention. The measurement system according to the present invention is normally in the standby mode S1 when there is no command to each measurement device 3. From the standby mode S1, it is possible to shift to three flows (time synchronization / communication path confirmation flow S2, periodic measurement / periodic data transmission flow S3, temporary measurement / temporary data transmission flow S4), and each flow is completed. Then, it returns to standby mode S1 again.

  Next, the time synchronization / communication path confirmation flow S2 will be described. The time synchronization in the present invention is to synchronize the time of the time measuring unit between each measuring device 3 and the data recording device 1 in order to synchronize the timing of regular measurement or the like. Also, the communication path confirmation in the present invention is to confirm whether all the measuring devices 3 are in a state where they can communicate with the data recording device 1 directly or by relay wireless communication.

  FIG. 3 (b) shows details of the time synchronization / communication path confirmation flow S2 described in FIG. 3 (a). Each measuring device 3 shifts to the external trigger reception mode S5 at regular intervals. At that time, it is confirmed whether or not a start trigger for time synchronization and communication path confirmation is transmitted from the data recording device 1 (S21). When the measuring device 3 is out of the communication range of the data recording device 1, the trigger is received by relay wireless communication via the remaining measuring device 3. The measuring apparatus 3 that has received the trigger shifts to S7 in the transmission / reception mode, and performs time synchronization and communication path confirmation (S22). It is confirmed that there is no abnormality (S23), and when there is an abnormality, adjustment is performed (S24). When the abnormality is eliminated, the process is completed, and the process proceeds to the standby mode S1 again.

  When the time synchronization is abnormal, the time is adjusted, and when the communication path is abnormal (when some communication paths are blocked by an obstacle or the like), it is reconfirmed whether communication is possible on the avoidance communication path. When the communication path is abnormal, it is technically possible to establish a bypass communication path autonomously by allowing the measurement devices 3 to communicate with each other. However, in civil engineering measurement, since the measuring device 3 is systematically arranged along the structure, it is possible to set an avoidance communication path at the time of abnormality in advance, thereby reducing the number of times of communication at the time of abnormality, Power supply life can be extended.

FIG. 4 shows details of the periodic measurement / periodic data transmission flow S3 shown in FIG. In this case, the control unit 13 (see FIG. 2) is intermittently operated by the trigger from the time measuring unit 11 to determine the type of trigger (S8). If the trigger is related to the regular measurement designated time (S31), the process proceeds to measurement mode S6, and measurement S32 and data storage S33 are performed. If the trigger is related to regular data transmission (S34), the process proceeds to transmission / reception mode S7 and data transmission is performed (S35). When all the processes are completed, the process again shifts to the standby mode S1.
The frequency of periodic measurement and periodic data transmission can be set as appropriate based on the life of the power source, the frequency of confirmation of measurement data, and the like. The setting can be changed by a command from the data recording device. In civil engineering measurement, periodic measurement is generally performed several times a day, and periodic data transmission is generally performed several times a year.

  FIG. 5 shows details of the temporary measurement / temporary data transmission flow S4 shown in FIG. Temporary measurement and temporary data transmission are used when it is desired to measure data temporarily for sudden events such as natural disasters. When transitioning to the external trigger reception mode (S5), if a temporary measurement trigger or a temporary data transmission trigger is received, each trigger type is determined. If the trigger is related to temporary measurement (S41), the process proceeds to measurement mode S6, and measurement S42 and data storage S43 are performed. If the trigger is related to temporary data transmission (S44), the process proceeds to transmission / reception mode S7 and data transmission is performed (S45). When all the processes are completed, the process again shifts to the standby mode S1.

[Mode conversion and measurement flow]
Next, mode conversion and measurement flow in the measurement apparatus of the present invention will be described.
FIG. 6 shows the relationship between the mode conversion of the measurement apparatus 3 of the present invention and the measurement flow shown in FIG.
As shown in the figure, the measuring device 3 is in a standby mode S1 when there is no processing. In the standby mode S1, only a current for operating the timer unit 11 is required as an operating current, and the power consumption is suppressed most. Generally, the maximum working current is 10 μA or less.

  The measuring device 3 shifts to the external trigger reception mode S5 for a very short time (several milliseconds) at regular intervals. In that case, since the external signal reception operation is performed, the maximum operating current may exceed 50 mA.

When an external signal is received, the process proceeds to measurement mode S6 depending on the signal type. In the measurement operation (S32, S42), first, power is supplied to the sensor, the sensor is energized for several tens of seconds, and then measurement processing is performed for several seconds. Thereafter, the sensor power supply is turned off. Note that when the measurement data measurement interval is equal to or less than a certain value (for example, 10 minutes or less), the amount of power consumed by turning on and off the sensor power increases, so the sensor power is always turned on. In the data storage operation (S33, S43), an operation of writing the measured data in the storage unit is performed. In general, the maximum working current exceeds 10 mA.
Transition to the transmission / reception mode S7 is also performed by an external signal. At that time, it transmits / receives to / from the data recording device, transfers stored data, changes operation settings such as measurement control methods, and the like. In order to transmit stored data, the maximum operating current may exceed 100 mA.

Next, the example which applied the equipment monitoring system using the radio | wireless communication of this invention to landslide monitoring is shown.
In general, the target structure is an open trench made of reinforced concrete. In this trench, there is a landslide block with a size of several hundred meters in plan, and there is an open trench across the landslide block, so the landslide causes deformation such as cracks in the concrete. ing.

FIG. 7 shows a configuration when the equipment monitoring system using wireless communication of the present invention is applied to landslide monitoring. An inspector brings a data recording device and a control personal computer to the site and wirelessly transmits each measurement data. Remote automatic collection can be performed by communication.
Next, FIG. 9 shows an example of measurement items and sensors used at the point. As shown in the table, the wireless communication path 1 measures landslide displacement, concrete crack width, temperature, and concrete temperature using an extensometer, a uniaxial crack displacement meter, and a thermometer. In the path 2, the inclination angle, the concrete crack width, the air temperature, and the concrete temperature are measured using an inclinometer, a biaxial crack displacement meter, and a thermometer.

  FIG. 8 shows a result of data collection on the relationship between the crack displacement of the measuring device No. 1 and the concrete temperature of the measuring device No. 2 in the above-described configuration. The data in FIG. 8 is a measurement result at 15-minute intervals. Since the measurement period is short, it has not yet been evaluated to evaluate the change in crack displacement over time, but it can be seen that the crack displacement is a change of about -0.01 mm with respect to the change in the concrete temperature of 1 ° C. Although the resolution of A / D conversion is 16 bits, clear linearity was confirmed in the relationship between crack width and temperature, and it was confirmed that the measurement accuracy was sufficient.

  The facility monitoring system using wireless communication according to the present invention is a facility monitoring system capable of grasping cracks, subsidence, landslides, etc. of civil engineering facilities and surrounding ground, and can perform multi-point measurement over a long period of time. Since it is unnecessary, it can be used as a highly reliable equipment monitoring system that can also handle temporary measurements in an emergency. In addition, since the measuring device of the present invention has good connectivity with various commercially available physical quantity measuring sensors, it is possible to construct an equipment monitoring system capable of measuring on a multifaceted scale.

It is a block diagram of the equipment monitoring system using the radio | wireless of this invention. It is a block diagram of the measuring device of this invention. It is a flowchart of the measurement system in this invention. It is a flowchart of the measurement system in this invention. It is a flowchart of the measurement system in this invention. It is a flowchart showing the relationship between mode conversion and measurement flow in the present invention. It is the block diagram which applied the equipment monitoring system and measuring device of this invention to the landslide monitoring system. It is a graph showing the relationship between concrete temperature and crack displacement. It is a graph showing the example of a measurement item and a use sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Data recording device 2 Measuring system 3 Measuring device 4 Sensor 11 Timekeeping part 12 Power supply part 13 Control part 14 Storage part 15 Wireless transmission / reception part 16 Conversion part 17 Connection part
A equipment monitoring system S1 standby mode S2 time synchronization / communication path confirmation flow S3 periodic measurement / periodic data transmission flow S4 temporary measurement / temporary data transmission flow S5 external trigger reception mode S6 measurement mode S7 transmission / reception mode

Claims (4)

In a facility monitoring system using wireless communication comprising a plurality of measuring devices that measure a predetermined physical quantity, a data recording device that collects and records information obtained by the measuring device, and a personal computer that controls the data recording device ,
A predetermined one of the plurality of measuring devices performs wireless communication with the data recording device or the remainder of the plurality of measuring devices by relay wireless communication, and synchronization of measurement time with the remaining portion of the measuring device by intermittent transmission and reception; A facility monitoring system using wireless communication, which adjusts a communication path, measures a physical quantity at a predetermined sampling interval, and transmits the obtained physical quantity measurement value to the data recording device.   The equipment monitoring system using wireless communication according to claim 1, wherein the measurement device stores measurement data of a predetermined physical quantity, and then transmits the measurement data to the data recording device.   A predetermined one of the measuring devices continuously enters a trigger signal reception mode at a predetermined interval for a predetermined time, and receives a trigger signal from the data recording device or a trigger signal transferred from the remainder of the measuring device. 3. The facility monitoring system using wireless communication according to claim 2, wherein a physical quantity is measured at the determined timing and the result is transmitted to the data recording device.   4. The facility monitoring using wireless communication according to claim 3, wherein the measuring device predetermines a communication route when each of the measuring devices is communicable and an alternative communication route when communication is impossible. system.

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